considering extended content-type header format (#62)

* considering extended content-type header format

* adding content-type parsing unit tests

index.js

@@ -65,7 +65,13 @@ module.exports = fp(function from (fastify, opts, next) {
       } else {
         // Per RFC 7231 §3.1.1.5 if this header is not present we MAY assume application/octet-stream
         const contentType = req.headers['content-type'] || 'application/octet-stream'
-        body = contentType.toLowerCase() === 'application/json' ? JSON.stringify(this.request.body) : this.request.body
+        // detect if body should be encoded as JSON
+        // supporting extended content-type header formats:
+        // - https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Type
+        const shouldEncodeJSON = contentType.toLowerCase().indexOf('application/json') === 0
+        // transparently support JSON encoding
+        body = shouldEncodeJSON ? JSON.stringify(this.request.body) : this.request.body
+        // update origin request headers after encoding
         headers['content-length'] = Buffer.byteLength(body)
         headers['content-type'] = contentType
       }

test/full-post-extended-content-type.js

@@ -0,0 +1,59 @@
+'use strict'
+
+const t = require('tap')
+const Fastify = require('fastify')
+const From = require('..')
+const http = require('http')
+const get = require('simple-get')
+
+const instance = Fastify()
+instance.register(From)
+
+t.plan(9)
+t.tearDown(instance.close.bind(instance))
+
+const target = http.createServer((req, res) => {
+  t.pass('request proxied')
+  t.equal(req.method, 'POST')
+  t.equal(req.headers['content-type'].startsWith('application/json'), true)
+  var data = ''
+  req.setEncoding('utf8')
+  req.on('data', (d) => {
+    data += d
+  })
+  req.on('end', () => {
+    t.deepEqual(JSON.parse(data), { hello: 'world' })
+    res.statusCode = 200
+    res.setHeader('content-type', 'application/json')
+    res.end(JSON.stringify({ something: 'else' }))
+  })
+})
+
+instance.post('/', (request, reply) => {
+  reply.from(`http://localhost:${target.address().port}`)
+})
+
+t.tearDown(target.close.bind(target))
+
+instance.listen(0, (err) => {
+  t.error(err)
+
+  target.listen(0, (err) => {
+    t.error(err)
+
+    get.concat({
+      url: `http://localhost:${instance.server.address().port}`,
+      method: 'POST',
+      body: JSON.stringify({
+        hello: 'world'
+      }),
+      headers: {
+        'content-type': 'application/json;charset=utf-8'
+      }
+    }, (err, res, data) => {
+      t.error(err)
+      t.equal(res.headers['content-type'], 'application/json')
+      t.deepEqual(JSON.parse(data.toString()), { something: 'else' })
+    })
+  })
+})